This invention relates to locks with sensors, and particularly a lock incorporating sensing and/or switching equipment therein in order to provide signals to an external source relating to the condition of the lock.
Locks are, of course, well known and are available in many different forms and configurations. For the most part, however, locks comprise some form of housing which accommodates a reciprocating latch or lever, the latch being movable between an unlocked withdrawn position and a locked extended position. In the withdrawn position, the latch would normally be contained within the housing, while in the extended position, the latch would engage an external and adjacent object to effect the locking operation. The latch would normally be movable between the withdrawn and extended position in response to the rotation of a key in the lock, or rotation of a handle, although such movements may also be in response to electrical, magnetic, pneumatic or other types of mechanical activation.
It is also known to provide external sensors with respect to such locks. Conventionally, a sensing switch or other device may be located externally of the lock, in order to sense or determine the position of the lever. The mechanical movement of the lever into the extended position has the effect of activating the sensor in one way to provide signals as to its condition, while the sensor would be activated in another manner to indicate the withdrawn or unlocked position of the lever.
It may be important to determine the position of the latch, namely, whether in the extended or retracted position, so that devices or systems can be connected to the lock and react according to the position of the latch. For example, the lock may be connected to an alarm system, such that when the lock is moved from the locked to an unlocked position while the alarm is operational, a signal will be provided to trigger the alarm. The lock may also be connected to video and/or audio recording equipment, heating and cooling systems, lighting systems, computers and/or other recording instruments to collect information on personnel or objects entering or leaving a particular area, especially areas which contain information or products which may be of a classified or confidential nature.
According to one aspect of the invention, there is provided a lock with sensor comprising: a housing defining a chamber; a latch retractor located within the chamber of the housing and being movable relative thereto between a retracted position wherein the latch retractor is substantially within the housing and an extended position wherein the latch retractor extends at least partially outside of the housing; and a sensor mechanism having a fixed switch portion located within the chamber and a movable switch activator portion, the switch activator portion being mounted so as to move with the latch retractor and thereby activate and deactivate the switch portion respectively.
According to another aspect of the invention, there is provided a method of detecting the position of a latch retractor within a housing of a lock, the latch retractor being movable between a retracted position and an extended position, the method comprising: mounting a switch member at a fixed location within the housing of the lock; mounting a switch actuator member on the latch mechanism within the housing, wherein the switch actuator member operatively engages and activates the switch member in one of the retracted or extended positions, and is remote from the switch; and transmitting signals from the switch member, according to the position of the latch mechanism, to an external source component remote from the lock.
The invention provides a lock incorporating a sensing mechanism for detecting the locked or unlocked condition thereof. Preferably, the lock comprises a housing member with a movable latch or lever therein, the latch being movable between an unlocked withdrawn position and a locked extended position, the movement of the latch causing activation or deactivation of a switch member. Preferably, the switch member, upon detecting a change in the condition of the lock, provides a signal to an external component, the component functioning in a predetermined manner according to the condition of the lock.
Preferably, the sensing mechanism contained within the lock comprises a fixedly member within the housing, and a movable member which moves with the lever between the extended and the retracted position, such that the orientation of the movable member in relation to the fixed member is able to provide the appropriate signal as to the condition of the lock. The fixed member is conveniently an electric switch, which sends an electric signal to the external component. The movable member may comprise a pin, magnet, projection on the lever, or other physical means which, by virtue of its movement with the lever between the extended and retracted position, has the effect of activating or deactivating the switch.
The activation of the switch may cause different results at the external component, depending upon the nature of the external component. For example, when the latch is in the withdrawn position, it may switch off the external component, which may be a surveillance camera; on the other hand, it may switch on the external component, which may be a light. Thus, the movement of the latch and the movable means will have the effect of activating or deactivating the switch, with either one of these conditions being used by the external component according to the type of function it performs. In other words, the component, depending ion its nature, may be switched either on or off when the latch is in the withdrawn position. The lock with sensor of the invention would be used appropriately to activate or deactivate the component, as appropriate, when the latch is withdrawn.
The invention has particular application with respect to cylindrical locks, including those using pin tumblers which need to be properly aligned with respect to each other by a key in order to rotate the cylinder. However, the invention is not restricted to such locks, and can be used with any lock mechanism which includes a fixed housing and a movable lever therein.